Change: Invalidate build toolbars when NewGRFs are changed.

If NewGRFs are changed while a rail or road toolbar is open, the toolbar could refer to an invalid rail/road type. If so, close it.

src/rail_gui.cpp

@@ -468,6 +468,12 @@ struct BuildRailToolbarWindow : Window {
 	{
 		if (!gui_scope) return;
 
+		if (!ValParamRailType(this->railtype)) {
+			/* Close toolbar if rail type is not available. */
+			this->Close();
+			return;
+		}
+
 		bool can_build = CanBuildVehicleInfrastructure(VEH_TRAIN);
 		for (const WidgetID widget : can_build_widgets) this->SetWidgetDisabledState(widget, !can_build);
 		if (!can_build) {

src/road_gui.cpp

@@ -377,6 +377,13 @@ struct BuildRoadToolbarWindow : Window {
 	void OnInvalidateData([[maybe_unused]] int data = 0, [[maybe_unused]] bool gui_scope = true) override
 	{
 		if (!gui_scope) return;
+
+		if (!ValParamRoadType(this->roadtype)) {
+			/* Close toolbar if road type is not available. */
+			this->Close();
+			return;
+		}
+
 		RoadTramType rtt = GetRoadTramType(this->roadtype);
 
 		bool can_build = CanBuildVehicleInfrastructure(VEH_ROAD, rtt);

src/saveload/afterload.cpp

@@ -68,6 +68,7 @@
 #include <signal.h>
 
 #include "../safeguards.h"
+#include "window_func.h"
 
 extern Company *DoStartupNewCompany(bool is_ai, CompanyID company = INVALID_COMPANY);
 
@@ -3377,6 +3378,7 @@ void ReloadNewGRFData()
 	for (CompanyID i = COMPANY_FIRST; i < MAX_COMPANIES; i++) InvalidateWindowData(WC_COMPANY_COLOUR, i);
 	/* Update company infrastructure counts. */
 	InvalidateWindowClassesData(WC_COMPANY_INFRASTRUCTURE);
+	InvalidateWindowClassesData(WC_BUILD_TOOLBAR);
 	/* redraw the whole screen */
 	MarkWholeScreenDirty();
 	CheckTrainsLengths();